About AreaCodes.com

Our Mission

AreaCodes.com exists to be the most accurate, easiest-to-use area code reference on the internet. We cover all 366 active US area codes, 2,628 cities, and 50 states with detailed information about geographic coverage, time zones, overlay codes, and local context. Every page is free to access, with no registration required. Whether you're trying to figure out where a phone call came from, looking up which area code serves your city, or just curious about the history of the North American numbering system, you'll find what you need here.

Editorial Process

Our content goes through a multi-step process before publication. Area code assignments and geographic data are sourced from official NANPA records and cross-referenced against FCC filings. City-level data is verified against US Census records. Time zone assignments follow IANA timezone database standards. Each area code page is reviewed for accuracy, and we monitor NANPA announcements for new code assignments, splits, and overlays to keep our data current. When we publish editorial content — like scam alerts or regional profiles — our writers research local sources and news reports to ensure accuracy.

Our Data Sources

We believe in transparency about where our information comes from. The data on AreaCodes.com is compiled from these primary sources:

• NANPA (North American Numbering Plan Administration) — Official source for area code assignments, administered by Somos, Inc. under FCC oversight
• Federal Communications Commission (FCC) — Regulatory filings, numbering plan changes, and telecommunications policy
• US Census Bureau — City populations, geographic boundaries, and demographic data
• IANA Time Zone Database — Authoritative time zone assignments for geographic regions
• FTC Consumer Sentinel Network — Scam and fraud reporting data used in our safety alerts
• State Attorney General offices — State-specific scam alerts and consumer protection notices

The North American Numbering Plan

Area codes were introduced in 1947 when AT&T and the Bell System created the North American Numbering Plan (NANP). The original system included 86 area codes covering the United States and Canada. The plan was designed to replace operator-assisted calling with direct-dial long distance.

Original Numbering Rules

The original area codes followed specific rules: the first digit was 2-9, the second digit was always 0 or 1, and the third digit was 1-9. Codes with 0 as the middle digit were assigned to states with a single area code (like 202 for DC), while codes with 1 as the middle digit were for states with multiple codes. These rules were relaxed starting in 1995 as demand for numbers grew.

Splits vs. Overlays

Geographic Split: The existing area is divided into two or more regions, each getting its own area code. This was common through the 1990s but means some people must change their number.

Overlay: A new area code is added to the same geographic region as the existing code. New numbers get the new code, but existing numbers keep theirs. The tradeoff is that all local calls require 10-digit dialing. Overlays have become the standard approach since the early 2000s.

Area Codes Today

As of 2026, there are over 330 active area codes in the US. The explosive growth in phone numbers — driven by cell phones, fax machines, pagers, and internet lines — has led to many areas needing multiple codes. Major cities like New York, Los Angeles, Houston, and Chicago each have 4 or more area codes serving their metropolitan areas.

What is NANPA?

The North American Numbering Plan Administration (NANPA) is the organization responsible for managing area codes and phone number resources across the US, Canada, and 18 Caribbean nations. NANPA is currently administered by Somos, Inc. and operates under the oversight of the Federal Communications Commission (FCC).

Our Team

AreaCodes.com is operated by a small team of writers and data specialists who care about making telecommunications information accessible to everyone.

Corrections & Contact

Accuracy matters to us. If you spot an error on any page — a wrong city assignment, an outdated overlay code, a timezone discrepancy — please let us know. We investigate every report and issue corrections promptly. Reach us at info@areacodes.com or visit our contact page.